264 
Psyche 
[June 
On April 2, 1965, the same experiment was repeated, substituting 
n-butyric for n-valeric acid. Results were essentially the same. Fifty- 
five minutes after the start, 3 of the 4 triethanolamine-treated cocoons 
had been transported for distances of 40", 21", and 25.5" from the 
nest entrance and dropped ; although none of the n-butyric or oleic 
acid cocoons had been moved, there was a considerable deposit of 
earth particles about them. One control cocoon had been moved 
about 2 7 ', but none had been carried into the nest. Twenty minutes 
later, the triethanolamine group was still being moved at frequent 
intervals, and the oleic acid group was being heavily banked with 
earth grains. No attention was paid to the n-butyric acid groups. 
The strong impression left by these trials, and others like them, 
was that oleic acid, and to a lesser degree caproic acid stimulate in 
Myrmecia vindex both a burying reaction and sometimes the trans- 
port of objects so contaminated to refuse middens. No evidence of 
overt digging was seen. Formic acid seemed without effect. Tri- 
ethanolamine, however, functioned as an efficient excitant and at- 
tractant in higher concentrations. In lower concentrations it stimu- 
lated necrophoric behavior. The “conflict” behavior exhibited in 
the handling of some larvae and cocoons treated with several of these 
substances, when immatures were repeatedly taken into the nest, 
brought out again and discarded on a midden, then returned to the 
nest, sometimes through three or four cycles, was in several cases 
striking. 
Field Tests 
Reactions of workers of Myrmecia vindex to Oleic acid ; 
Caproic acid ; Formic tcid ; Methylbenzylamine 
It was of interest to conduct essentially similar tests with wild 
colonies in the field. A large and active colony of M. vindex in 
Kings Park, Perth, West Australia (a part of the same population 
from which the colonies had been taken for laboratory tests), was 
selected. It included approximately 200 workers, had a single large 
entrance-hole, and a well-defined crater. Since workers of this 
population show a predominantly crepuscular and nocturnal foraging 
pattern in warm weather, tests were begun in the evening. 
At 7:25 p.m., as dusk was gathering, 5 white cards, of dimensions 
3” X 5", were mounted on the nest crater, approximately equi- 
distant from the entrance. Twenty-five cocoons, obtained from a 
neighboring colony, were impregnated with 3 drops of test substance, 
with 7 retained as untreated controls. The arrangement and treat- 
ments were as shown below: 
